Semiconductor devices having staggered air gaps

ABSTRACT

A semiconductor device includes a substrate, a plurality of first conductive patterns disposed on the substrate and a plurality of second conductive patterns disposed on the first conductive patterns. Respective air gaps are disposed between adjacent ones of the first conductive patterns overlying a first region of the substrate, while adjacent ones of the first conductive patterns overlying a second region of the substrate do not have air gaps disposed therebetween. The air gaps may include first air gaps, and the device may further include second air gaps disposed between adjacent ones of the second conductive patterns in the second region. Adjacent ones of the second conductive patterns overlying a second region of the substrate may not have air gaps disposed therebetween.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/679,786, filed Apr. 6, 2015 in the United States Patent and TrademarkOffice and claims priority to Korean Patent Application No.10-2014-0041160 filed on Apr. 7, 2014 in the Korean IntellectualProperty Office (KIPO), the contents of each are herein incorporated byreference in their entireties.

TECHNICAL FIELD

The present inventive concepts relate to semiconductor devices and, moreparticular, semiconductor devices including air gaps.

DESCRIPTION OF RELATED ART

It is desirable for semiconductor devices to be highly integrated,dense, with low power consumption, high speed, and other performancecharacteristics. Some highly integrated semiconductor devices includemultiple interconnection layers, each including a plurality ofconductive patterns. As feature sizes of semiconductor devices havedecreased, distances between adjacent conductive patterns have beennarrowed. Because of the reduced separation, interference between theadjacent conductive patterns may be generated by parasitic capacitance,which may negatively impact data transfer. Therefore, various techniqueshave been proposed to reduce parasitic capacitance between adjacentconductive patterns.

Some of these techniques involve the use of air gaps to reducecapacitive coupling between conductors. Such techniques are described,for example, in U.S. Pat. No. 7,253,095 to Lur et al., U.S. Pat. No.8,034,693 to Shibata et al, and U.S. Pat. No. 8,642,252 to Clevenger etal.

SUMMARY

According to some embodiments, a semiconductor device includes asubstrate, a plurality of first conductive patterns disposed on thesubstrate, and a plurality of second conductive patterns disposed on thefirst conductive patterns. Respective air gaps are disposed betweenadjacent ones of the first conductive patterns overlying a first regionof the substrate, while adjacent ones of the first conductive patternsoverlying a second region of the substrate do not have air gaps disposedtherebetween. The air gaps may include first air gaps, and the devicemay further include second air gaps disposed between adjacent ones ofthe second conductive patterns overlying the second region of thesubstrate. Adjacent ones of the second conductive patterns overlying thefirst region of the substrate may not have air gaps disposedtherebetween.

The first and second conductive patterns may be conductive linesextending along the same direction. The first and second conductivepatterns may include conductive lines extending along a first directionand the first region of the substrate may be adjacent the second regionalong a second direction transverse to the first direction.

In some embodiments, the second air gaps do not overlie the first airgaps.

In further embodiments, the semiconductor device may further include aninterlayer dielectric layer between the first conductive patterns in thesecond region and a mask pattern on the interlayer dielectric layer.

In some embodiments, the first conductive patterns may include aplurality of conductive plugs vertically overlapped by the mask pattern.Sidewalls of the conductive plugs may contact the interlayer dielectriclayer.

In some embodiments, the mask pattern overlies the second region of thesubstrate but does not overlie the first region of the substrate. Themask pattern may have a mechanical strength greater than that of theinterlayer dielectric layer.

According to further embodiments, the semiconductor device furtherincludes third conductive patterns on the second conductive patterns.Respective third air gaps are disposed between adjacent ones of thethird conductive patterns and overlying the first region of thesubstrate, wherein adjacent ones of the third conductive patternsoverlying the second region of the substrate do not have air gapsdisposed therebetween.

According to further embodiments, the device may further include asecond interlayer dielectric layer between the second conductivepatterns in the first region and a second mask pattern on the secondinterlayer dielectric layer. The second mask pattern may overlie thefirst region of the substrate but not overlie the second region of thesubstrate. The second mask pattern may overlap the first mask pattern.

The semiconductor device may further include a first metal oxynitridelayer disposed between the first mask pattern and the first interlayerdielectric layer and a second metal oxynitride layer disposed betweenthe second mask pattern and the second interlayer dielectric layer.

Further embodiments provide a semiconductor device including a substrateand a plurality of first conductive patterns disposed on the substrate.Respective first air gaps are disposed between adjacent ones of thefirst conductive patterns overlying a first region of the substrate. Thedevice further includes a plurality of second conductive patternsdisposed on the first conductive patterns. Respective second air gapsare disposed between adjacent ones of the second conductive patternsoverlying a second region of the substrate. Adjacent ones of the firstconductive patterns overlying the second region of the substrate do nothave air gaps disposed therebetween and adjacent ones of the secondconductive patterns overlying the first region of the substrate do nothave air gaps disposed therebetween.

The device may further include a first interlayer dielectric layerdisposed between the first conductive patterns overlying the secondregion of the substrate and a second interlayer dielectric layerdisposed between the second conductive patterns overlying the firstregion of the substrate. The device may also include a first maskpattern disposed on the first interlayer dielectric layer overlying thesecond region of the substrate. The device may further include a secondmask pattern disposed on the second interlayer dielectric layeroverlying the first region of the substrate and a plurality of thirdconductive patterns disposed on the second mask pattern.

Further embodiments provide a semiconductor device including a substrateand a plurality of first conductive patterns disposed on the substrate.Respective first air gaps are disposed between adjacent ones of theplurality of first conductive patterns overlying a first region of thesubstrate. The device further includes a plurality of second conductivepatterns disposed on the first conductive patterns. Respective secondair gaps are disposed between adjacent ones of the plurality of secondconductive patterns overlying a second region of the substrate. A maskpattern is disposed between the first conductive patterns and the secondconductive patterns and not overlapping the first air gaps.

Still further embodiments provide a semiconductor device including asubstrate, an interlayer dielectric layer disposed on the substrate,first conductive lines disposed in the interlayer dielectric layer andsecond conductive lines disposed in a recess in the interlayerdielectric layer. The device further includes a diffusion barrier layerdisposed on and between adjacent ones of the second conductive lines inthe recess in the interlayer dielectric layer. The diffusion barrierlayer defines respective air gaps between sidewalls of adjacent ones ofthe second conductive lines. The diffusion barrier layer may alsooverlie the first conductive lines and the device may further include astrengthening layer interposed between the interlayer dielectric layerand the diffusion barrier layer and overlying the first conductivelines. The strengthening layer may not overlie the second conductivelines.

According to further embodiments, the interlayer dielectric layercomprises a first interlayer dielectric layer, the diffusion barrierlayer comprises a first diffusion barrier layer, the air gaps comprisefirst air gaps, and the device further includes a second interlayerdielectric layer on the first barrier diffusion layer, third conductivelines disposed in the interlayer dielectric layer overlying the secondconductive lines, fourth conductive lines disposed in a recess in thesecond interlayer dielectric layer overlying the first conductive linesand a second diffusion barrier layer disposed on and between adjacentones of the fourth conductive lines in the recess in the secondinterlayer dielectric layer. The second diffusion barrier layer definesrespective second air gaps between sidewalls of adjacent ones of thefourth conductive lines. The first diffusion barrier layer may alsooverlie the first conductive lines and the device may further include afirst strengthening layer interposed between the first interlayerdielectric layer and the first diffusion barrier layer and overlying thefirst conductive lines. The second diffusion barrier may also overliethe third conductive lines and the device may further include a secondstrengthening layer interposed between the second interlayer dielectriclayer and the second diffusion barrier layer and overlying the thirdconductive lines.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the inventive concept will become moreapparent by describing in detail exemplary embodiments thereof withreference to the accompanying drawings of which:

FIG. 1 is a plan view illustrating semiconductor devices according tosome embodiments of the inventive concepts.

FIG. 2A is a cross-sectional view corresponding to line I-I′ of FIG. 1.

FIG. 2B is a cross-sectional view corresponding to line II-II′ of FIG.1.

FIG. 2C is a cross-sectional view corresponding to line III-III′ of FIG.1.

FIGS. 3 through 11 are cross-sectional views illustrating operations forfabricating semiconductor devices according to some embodiments of theinventive concepts.

FIG. 12 is a plan view illustrating semiconductor devices according tofurther embodiments of the inventive concepts.

FIG. 13 is a cross-sectional view corresponding to line I-I′ of FIG. 12.

FIG. 14 is a plan view illustrating semiconductor devices according tostill further embodiments of the inventive concepts.

FIG. 15a is a cross-sectional view corresponding to line I-I′ of FIG.14.

FIG. 15b is a cross-sectional view corresponding to line II-II′ of FIG.14.

FIG. 15c is a cross-sectional view corresponding to line III-III′ ofFIG. 14.

FIG. 15d is a cross-sectional view corresponding to line IV-IV′ of FIG.14.

FIG. 16 is a cross-sectional view, corresponding to line I-I′ of FIG. 1,illustrating semiconductor devices according to some embodiments of theinventive concepts.

FIG. 17 is a cross-sectional view illustrating semiconductor devicesaccording to some embodiments of the inventive concepts.

FIG. 18 is a plan view illustrating semiconductor devices according tostill further embodiments of the inventive concepts.

FIG. 19 is a cross-sectional view corresponding to line I-I′ of FIG. 18.

FIG. 20 is a plan view illustrating semiconductor devices according toadditional embodiments of the inventive concepts.

FIG. 21 is a cross-sectional view corresponding to line I-I′ of FIG. 20.

FIG. 22 is a block diagram of electronic systems including semiconductordevices according to some embodiments of the inventive concepts.

DETAILED DESCRIPTION

Exemplary embodiments of the inventive concepts will now be describedmore fully hereinafter with reference to the accompanying drawings;however, they may be embodied in different forms and should not beconstrued as limited to the exemplary embodiments set forth herein.

It will be understood that when an element is referred to as being “on,”“connected” or “coupled” to another element, it can be directly on,connected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as “contacting,” orbeing “directly on,” “directly connected” or “directly coupled” toanother element, there are no intervening elements present. Other wordsused to describe the , relationship between elements or layers should beinterpreted in a like fashion (e.g., “between” versus “directlybetween,” “adjacent” versus “directly adjacent,” “under” versus“directly under”).

It will be understood that, although the terms “first”, “second”, etc.,may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. Unless the contextindicates otherwise, these terms are only used to distinguish oneelement, component, region, layer or section from another element,component, region, layer or section. Thus, a first element, component,region, layer or section discussed below could be termed a secondelement, component, region, layer or section without departing from theteachings of example embodiments.

In the figures, the dimensions of layers and regions may be exaggeratedfor clarity of illustration.

Spatially relative terms, e.g., “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe the relationship of one element or feature to anotherelement(s) or feature(s), as illustrated in the figures. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation in addition tothe orientation depicted in the figures. For example, if the device inthe figures is turned over, elements described as “below” or “beneath”other elements or features would then be oriented “above” the otherelements or features. Thus, the exemplary term “below” can encompassboth an orientation of above and below. The device may be otherwiseoriented (rotated 90 degrees or at other orientations) and the spatiallyrelative descriptors used herein interpreted accordingly.

As used herein, the term “and/or” includes any and all combinations ofone or more of the associated listed items. The use of the terms “a” and“an” and “the” and similar referents in the context of describingembodiments (especially in the context of the following claims) are tobe construed to cover both the singular and the plural, unless otherwiseindicated herein or clearly contradicted by context. The terms“comprising,” “having,” “including,” and “containing” are to beconstrued as open-ended terms (i.e., meaning “including, but not limitedto”) unless otherwise noted.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art. It is noted that the use of any and all examples, or exemplaryterms provided herein is intended merely to better illuminate theexample embodiments and is not a limitation on the scope of theinventive concepts unless otherwise specified.

Example embodiments will be described with reference to perspectiveviews, cross-sectional views, and/or plan views. The profile of anexample view may be modified according to, e.g., manufacturingtechniques and/or allowances. Accordingly, the example embodiments arenot intended to limit the scope, but cover all changes and modificationsthat can be caused due to, e.g., a change in manufacturing process.Thus, regions shown in the drawings are illustrated in schematic formand the shapes of the region are presented simply by way of illustrationand not as a limitation.

Unless the context indicates otherwise, terms such as “same,” “equal,”“planar,” or “coplanar,” as used herein when referring to orientation,layout, location, shapes, sizes, amounts, or other measures do notnecessarily mean an exactly identical orientation, layout, location,shape, size, amount, or other measure, but are intended to encompassnearly identical orientation, layout, location, shapes, sizes, amounts,or other measures within acceptable variations that may occur, forexample, due to manufacturing processes. The term “substantially” may beused herein to reflect this meaning.

Although corresponding plan views and/or perspective views of somecross-sectional view(s) may not be shown, the cross-sectional view(s) ofdevice structures illustrated herein provide support for a plurality ofdevice structures that extend along two different directions as would beillustrated in a plan view, and/or in three different directions aswould be illustrated in a perspective view. The two different directionsmay or may not be orthogonal to each other. The three differentdirections may include a third direction that may be orthogonal to thetwo different directions. The plurality of device structures may beintegrated in a same electronic device. For example, when a devicestructure (e.g., a memory cell structure or a transistor structure) isillustrated in a cross-sectional view, an electronic device may includea plurality of the device structures (e.g., memory cell structures ortransistor structures), as would be illustrated by a plan view of theelectronic device. The plurality of device structures may be arranged inan array and/or in a two-dimensional pattern.

Hereinafter, exemplary embodiments of the inventive concepts will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a plan view illustrating a semiconductor device according toan exemplary embodiment of the inventive concepts. FIGS. 2a, 2b and 2care cross-sectional views corresponding to lines I-I′, II-II′ andIII-III′ of FIG. 1, respectively.

Referring to FIGS. 1 and 2 a through 2 c, a semiconductor substrate 1may include a first region A and a second region B. The first region Amay be disposed at a left side and the second region B may be disposed aright side. The substrate 1 may include a device isolation layer and/ortransistors. A first interconnection layer L1, a second interconnectionlayer L2, a third interconnection layer L3, and a fourth interconnectionlayer L4 may be sequentially stacked on the substrate 1.

The first interconnection layer L1 may include a first interlayerdielectric layer 3, a plurality of eleventh conductive patterns 10 a, aplurality of twelfth conductive patterns 10 b, a thirteenth conductivepattern 10 c, and a plurality of first air gaps AG1. The firstinterlayer dielectric layer 3 may include a silicon oxide layer having alower dielectric constant, for example, a SiOCH layer and/or aporous-SiOCH layer. A first recess R1 may be formed in the firstinterlayer dielectric layer 3 disposed in the second region B. Theeleventh conductive patterns 10 a may be formed in the first region Aand the twelfth conductive patterns 10 b may be formed in the secondregion B. The thirteenth conductive pattern 10 c may be formed at aboundary of the first region A and the second region B. A portion of thethirteenth conductive pattern 10 c and the twelfth conductive patterns10 b are disposed in the first recess R1. Another portion of thethirteenth conductive pattern 10 c and sidewalls of the eleventhconductive patterns 10 a may be covered by the first interlayerdielectric layer 3. The eleventh through thirteenth conductive patterns10 a through 10 c may be line patterns formed in parallel and may extendalong a direction, for example, Y-direction.

Each of the eleventh through thirteen conductive patterns 10 a, 10 b,and 10 c may include a first wiring line 7 and a first metal diffusionbarrier layer 5 that covers a bottom and sidewalls of the first wiringline 7. The first wiring line 7 may be formed of a metal material, forexample, aluminum (Al) and/or tungsten (W). The first metal diffusionbarrier layer 5 may include at least one of titanium (Ti), titaniumnitride (TiN), tantalum (Ta), tantalum nitride (TaN), ruthenium (Ru),cobalt (Co), manganese (Mn), tungsten nitride (WN), nickel (Ni) ornickel boron (NiB). A first capping layer 9 a may be formed on theeleventh through thirteen conductive patterns 10 a, 10 b, and 10 c. Thefirst capping layer 9 a may be formed of a metal nitride including atleast one of tantalum (Ta), ruthenium (Ru), cobalt (Co), manganese (Mn),titanium (Ti), tungsten (W), nickel (Ni), aluminum (Al) or a mixturethereof.

In the first region A, upper surfaces of the eleventh conductivepatterns 10 a, a portion of an upper surface of the thirteenthconductive pattern 10 c, and an upper surface of the first interlayerdielectric layer 3 may be covered by a first mask pattern M1. The firstmask pattern M1 may include at least one of silicon carbon nitride(SiCN), silicon nitride (SiN), or silicon oxycarbide (SiOC). The firstmask pattern M1 may have a mechanical strength greater than that of thefirst interlayer dielectric layer 3. An upper surface of the first maskpattern M1 may be covered by a first insulating diffusion barrier layer11. The first insulating diffusion barrier layer 11 may include at leastone of silicon carbon nitride (SiCN), silicon nitride (SiN), or siliconoxycarbide (SiOC). The first insulating diffusion barrier layer 11 mayextend to the second region B and cover the upper surfaces and bothsidewalls of the twelfth conductive patterns 10 b and a sidewall of thethirteenth conductive pattern 10 c. In the second region B, the firstinsulating diffusion barrier layer 11 may define the first air gaps AG1between adjacent ones of the twelfth conductive patterns 10 b.

Next, the second interconnection layer L2 will be explained in detail.The second interconnection layer L2 may be formed on the firstinterconnection layer L1 and have, a similar structure. However, aplurality of air gaps may be formed in a different side, i.e., thesecond region B, in the second interconnection layer L2.

The second interconnection layer L2 may include a second interlayerdielectric layer 13. A second recess R2 may be formed in the secondinterlayer dielectric layer 13 in the first region A. A plurality oftwenty-first conductive patterns 20 a may be formed in the second recessR2. In the second region B, a plurality of twenty-second conductivepatterns 20 b may be formed in the second interlayer dielectric layer13. A twenty-third conductive pattern 20 c may be formed at a boundaryof the first region A and the second region B. Each of the twenty-firstthrough twenty-third conductive patterns 20 a, 20 b, and 20 c mayinclude a second wiring line 17 and a second metal diffusion barrierlayer 15. Upper surfaces of the twenty-first through twenty-thirdconductive patterns 20 a, 20 b, and 20 c may be covered by a secondcapping layer 19 a. In the second region B, upper surfaces of thetwenty-second conductive patterns 20 b and a portion of the twenty-thirdconductive pattern 20 c may be covered by a second mask pattern M2. Asecond insulating diffusion barrier layer 21 may be formed on the secondmask pattern M2. The second insulating diffusion barrier layer 21 maycover upper surfaces of the twenty-first conductive patterns 20 a andsidewalls thereof. Second air gaps AG2 may be formed between adjacentones of the twenty-first conductive patterns 20 a.

A third interconnection layer L3 may be formed on the secondinterconnection layer L2 and may have substantially the same structureas the first interconnection layer L1.

The third interconnection layer L3 may include a third interlayerdielectric layer 23. A third recess R3 may be formed in the thirdinterlayer dielectric layer 23 in the second region B. A plurality ofthirty-first conductive patterns 30 a may be formed in the thirdinterlayer dielectric layer 23 and a plurality of thirty-secondconductive patterns 30 b may be formed in the third recess R3. Athirty-third conductive pattern 30 c may be formed at a boundary of thefirst region A and second region B. Each of the thirty-first throughthirty-third conductive patterns 30 a, 30 b, and 30 c may include athird wiring line 27 and a third metal diffusion barrier layer 25. Uppersurfaces of the thirty-first through thirty-third conductive patterns 30a, 30 b, and 30 c may be covered by a third capping layer 29 a. In thefirst region A, upper surfaces of the thirty-first conductive patterns30 a and a portion of the thirty-third conductive pattern 30 c may becovered by a third mask pattern M3. A third insulating diffusion barrierlayer 31 may be formed on the third mask pattern M3. The thirdinsulating diffusion barrier layer 31 may cover upper surfaces of thethirty-second conductive patterns 30 b and sidewalls thereof. Third airgaps AG3 may be formed at between adjacent ones of the thirty-secondconductive patterns 30 b.

A fourth interconnection layer L4 may be formed on the thirdinterconnection layer L3 and may have substantially the same structureas the second interconnection layer L2.

The fourth interconnection layer L4 may include a fourth interlayerdielectric layer 33. A fourth recess R4 may be formed in the fourthinterlayer dielectric layer 33 in the first region A. A plurality offorty-first conductive patterns 40 a may be formed in the fourth recessR4. In the second region B, a plurality of forty-second conductivepatterns 40 b may be formed in the fourth interlayer dielectric layer33. A forty-third conductive pattern 40 c may be formed at a boundary ofthe first region A and the second region B. Each of the forty-firstthrough forty-third conductive patterns 40 a, 40 b, and 40 c may includea fourth wiring line 37 and a fourth metal diffusion barrier layer 35.Upper surfaces of the forty-first through forty-third conductivepatterns 40 a, 40 b, and 40 c may be covered by a fourth capping layer39 a. In the second region B, upper surfaces of the forth-secondconductive patterns 40 b and a portion of the forty-third conductivepattern 40 c may be covered by a fourth mask pattern M4. A fourthinsulating diffusion barrier layer 41 may be formed on the fourth maskpattern M4. The fourth insulating diffusion barrier layer 41 may extendto cover upper surfaces of the forty-first conductive patterns 40 a andsidewalls thereof. Fourth air gaps AG4 may be formed at between adjacentones of the forty-first conductive patterns 40 a.

The eleventh, twenty-first, thirty-first, and forty-first conductivepatterns 10 a, 20 a, 30 a, and 40 a may vertically overlap. The twelfththrough forty-second conductive patterns 10 b, 20 b, 30 b, and 40 b mayvertical overlap. The thirteenth through forty-third conductive patterns10 c, 20 c, 30 c, and 40 c may vertically overlap.

The first air gaps AG1 are arranged so that they are not verticallyoverlapped by the second air gaps AG2. Instead, the first air gaps AG1may be overlapped by the second interlayer dielectric layer 13 and thesecond mask pattern M2. The first mask pattern M1 and the firstinterlayer dielectric layer 3 may be disposed below the second air gapsAG2.

The second air gaps AG2 are arranged so that they are not verticallyoverlapped by the third air gaps AG3. Instead, the second air gaps AG2may be vertically overlapped by the third interlayer dielectric layer 23and the third mask pattern M3. The second mask pattern M2 and the secondinterlayer dielectric layer 13 may be disposed below the third air gapsAG3.

The third air gaps AG3 are arranged such that they are not verticallyoverlapped by the fourth air gaps AG4. The third air gaps AG3 may bevertically overlapped by the fourth interlayer dielectric layer 33 andthe fourth mask pattern M4. The third mask pattern M3 and the thirdinterlayer dielectric layer 23 may be disposed below the fourth air gapsAG4.

Mechanical strength and reliability of semiconductor devicesmanufactured according to some embodiments of the inventive concepts maybe increased by forming the non-overlapped air gaps AG1 through AG4 inthe stacked interconnection layers. Furthermore, mechanical strength ofsemiconductor devices may be further increased by the mask patterns M1through M2. The thirteenth through forty-third conductive patterns 10 cthrough 40 c may help to increase the mechanical strength of thesemiconductor device. Signal transfer rate of the semiconductor devicemanufactured according to some embodiments of the inventive concepts maybe increased by the presence of the air gaps AG1 through AG4, which maydecrease parasitic capacitance between the conductive patterns in eachof the interconnection layers L1 through L4.

Various methods of manufacturing the semiconductor device according toexemplary embodiments of the inventive concepts will now be described.

FIGS. 3 through 11 are cross-sectional views illustrating a method ofmanufacturing a semiconductor device according to an exemplaryembodiment of the inventive concepts corresponding to FIG. 2A.

Referring to FIG. 3, a substrate 1 having a first region A and a secondregion B may be provided. A first interlayer dielectric layer 3 may beformed on the substrate 1. A plurality of line-type grooves may beformed in the first interlayer dielectric layer 3 by patterning thefirst interlayer dielectric layer 3. A first metal diffusion barrierlayer 5 may be conformally formed in the line-type grooves and aconductive layer may be formed on the first metal diffusion barrierlayer 5 in order to fill the line-type grooves. A planarization processmay be performed to the conductive layer and the first metal diffusionbarrier layer 5 to expose an upper surface of the first interlayerdielectric layer 3 and to form eleventh through thirteenth conductivepatterns 10 a, 10 b, and 10 c in the line-type grooves. A first cappinglayer 9 a may be formed on each of the eleventh through thirteenthconductive patterns 10 a, 10 b, and 10 c. The first capping layer 9 amay be formed by using a deposition process, for example, a chemicalvapor deposition process or an atomic layer deposition process. Thefirst capping layer 9 a may be formed by using, for example, anelectroplating process. The first capping layer 9 a may include, forexample, cobalt (Co). The first capping layer 9 a may be absent from theupper surface of the first interlayer dielectric layer 3.

Referring to FIG. 4, a first mask pattern M1 may be formed on the firstinterlayer dielectric layer 3 disposed in the first region A, leaving anupper surface of the first interlayer dielectric layer 3 disposed in thesecond region B exposed. The first mask pattern M1 may be formed bypatterning a mask layer after forming the mask layer entirely on thefirst interlayer dielectric layer 3. The first mask pattern M1 mayinclude at least one of silicon carbon nitride (SiCN), silicon nitride(SiN), or silicon oxycarbide (SiOC).

Referring to FIG. 5, a first recess R1 may be formed in the secondregion B by etching the first interlayer dielectric layer 3 using thefirst mask pattern M1 as an etch mask. Sidewalls of the twelfthconductive patterns 10 b and a sidewall of the thirteenth conductivepattern 10 c may be exposed in forming the first recess RI. The firstcapping layer 9 a may protect the twelfth conductive patterns 10 b andthe thirteenth conductive pattern 10 c from being damaged by an etchsource gas when the first recess R1 is formed using an etch process.

Referring to FIG. 6, a first insulating diffusion barrier layer 11 maybe formed on the upper surface of the substrate 1. The first insulatingdiffusion barrier layer 11 may be formed by using a deposition methodhaving a poor step coverage characteristic, e.g., a sputtering processor a physical vapor deposition process. Therefore, first air gaps AG1may be formed between adjacent ones of the twelfth conductive patterns10 b even though the first, insulating diffusion barrier layer 11 mayhave a uniform thickness on the first mask pattern M1. One of the firstair gaps AG1 may be formed between the thirteenth conductive pattern 10c and an adjacent one of the twelfth conductive patterns 10 b. A firstinterconnection layer L1 may comprise the first interlayer dielectriclayer 3, the eleventh conductive patterns 10 a, the twelfth conductivepatterns 10 b, the thirteenth conductive pattern 10 c, the first maskpattern M1, and the first air gaps AG1.

Referring to FIG. 7, a second interlayer dielectric layer 13 may beformed on the first interconnection layer L1. Twenty-first,twenty-second, and twenty-third conductive patterns 20 a, 20 b, and 20 cmay be formed in the second interlayer dielectric layer 13. A secondcapping layer 19 a may be formed on the twenty-first throughtwenty-third conductive patterns 20 a through 20 c.

Referring to FIG. 8, a second mask pattern M2 may be formed that coversthe second interlayer dielectric layer 13 in the second region B andexposes the second interlayer dielectric layer 13 in the first region A.Referring to FIG. 9, a second recess R2 may be formed in the firstregion A by etching the second interlayer dielectric layer 13 using thesecond mask pattern M2 as an etch mask. Sidewalls of the twenty-firstconductive patterns 20 a and a sidewall of the twenty-third conductivepattern 20 c may be exposed in forming the second recess R2. The secondcapping layer 19 a may protect the twenty-first conductive patterns 20 aand the twenty-third conductive pattern 20 c from being damaged by anetch source gas when the second recess R2 is formed using an etchprocess.

Referring to FIG. 10, a second insulating diffusion barrier layer 21 maybe formed on the upper surface of the substrate 1. The second insulatingdiffusion barrier layer 21 may be formed by using a deposition methodhaving a poor step coverage characteristic, e.g., a sputtering processor a physical vapor deposition process. Therefore, second air gaps AG2may be formed between adjacent ones of the twenty-first conductivepatterns 20 a even though the second insulating diffusion barrier layer21 may have a uniform thickness on the second mask pattern M2. One ofthe second air gaps AG2 may be formed between the twenty-thirdconductive pattern 20 c and an adjacent one of the twenty-firstconductive patterns 20 a. A second interconnection layer L2 may comprisethe second interlayer dielectric layer 13, the twenty-first conductivepatterns 20 a, the twenty-second conductive patterns 20 b, thetwenty-third conductive pattern 20 c, the second mask pattern M2, andthe second air gaps AG2.

Referring to FIG. 11, a third interconnection layer L3 may be formed onthe second interconnection layer L2. The third interconnection layer L3may be formed by using substantially the same process as the method offorming the first interconnection layer L1.

Referring to FIG. 2A again, a fourth interconnection layer L4 may beformed on the third interconnection layer L3. The fourth interconnectionlayer L4 may be formed by using substantially the same process as themethod of forming the second interconnection layer L2.

Semiconductor devices having first through fourth air gaps AG1 throughAG4 arranged such that air gaps of immediately adjacent layers do notoverlap by arranging the air gaps on alternating sides in successivelayers has been described. In further embodiments, semiconductor devicesmay have other arrangements of non-overlapping air gaps. Semiconductordevice having air gaps arranged alternately in each of theinterconnection layers will be described. For example, the first airgaps AG1 may be formed in the first interconnection layer L1 and thesecond air gaps AG2 may be formed in the third interconnection layer L3.The semiconductor device may not have any air gaps in the secondinterconnection layer L2 or in the fourth interconnection layer L4.

FIG. 12 is a plan view illustrating a semiconductor device according toanother exemplary embodiment of the inventive concepts. FIG. 13a is across-sectional view corresponding to line I-I′ of FIG. 12.

Referring to FIGS. 12 and 13, a semiconductor device may comprise firstthrough fourth interconnection layers L1, L2, L3, and L4 which aresequentially formed on a substrate 1. A plurality of first air gaps AG1may be formed in the first interconnection layer L1 and a plurality ofsecond air gaps AG2 may be formed in the third interconnection layer L3.There is no air gap in the second interconnection layer L2 and in thefourth interconnection layer L4. The semiconductor device shown in FIGS.12 and 13 may have substantially the same structure as the structuresshown in the second region B of FIGS. 1 and 2 a, respectively.

In detail, the first interconnection layer L1 may include a firstinterlayer dielectric layer 3. The first interlayer dielectric layer 3may have a first recess R1 formed therein. A plurality of firstconductive patterns 10 spaced apart from each other may be disposed inthe first recess R1. Upper surfaces of the first conductive patterns 10may be covered by a first capping layer 9 a and a first insulatingdiffusion barrier layer 11. The first insulating diffusion barrier layer11 may define first air gaps AG1 between adjacent ones of the firstconductive patterns 10.

The second interconnection layer L2 may include a second interlayerdielectric layer 13 covering the first interconnection layer L1. Aplurality of second conductive patterns 20 may be disposed in the secondinterlayer dielectric layer 13. There are no air gaps between the secondconductive patterns 20, i.e., the second interlayer dielectric layer 13may substantially fill spaces between the second conductive patterns 20.Upper surfaces of the second conductive patterns 20 may be covered by asecond capping layer 19 a. Upper surfaces of the second conductivepatterns 20 and the second interlayer dielectric layer 13 may be coveredby a second mask pattern M2. A second insulating diffusion barrier layer21 may be disposed on the second mask pattern M2. In some embodiments,the second mask pattern M2 and the second insulating diffusion barrierlayer 21 may be omitted.

The third interconnection layer L3 may include a third interlayerdielectric layer 23 covering the second interconnection layer L2. Thethird interlayer dielectric layer 23 may have a third recess R3 formedtherein. A plurality of third conductive patterns 30 spaced apart fromeach other may be disposed in the third recess R3. Upper surfaces of thethird conductive patterns 30 may be covered by a third capping layer 29a and a third insulating diffusion barrier layer 31. The thirdinsulating diffusion barrier layer 31 may define second air gaps AG2between adjacent ones the first conductive patterns 30.

The fourth interconnection layer L4 may include a fourth interlayerdielectric layer 33 covering the third interconnection layer L3. Aplurality of fourth conductive patterns 40 may be disposed in the fourthinterlayer dielectric layer 33. There are air gaps between the fourthconductive patterns 40, i.e., the fourth interlayer dielectric layer 33may substantially fill the spaces between adjacent ones of the fourthconductive patterns 40. Upper surfaces of the fourth conductive patterns40 may be covered by a fourth capping layer 39 a. Upper surfaces of thefourth conductive patterns 40 and the fourth interlayer dielectric layer33 may be covered by a fourth mask pattern M4. A fourth insulatingdiffusion barrier layer 41 may be disposed on the fourth mask patternM4. In some embodiments, the fourth mask pattern M4 and the fourthinsulating diffusion barrier layer 41 may be omitted.

As shown in FIG. 13, the semiconductor device may have air gaps in thefirst and third interconnection layers L1 and L3. However, in anotherexemplary embodiment, the semiconductor device may have air gaps in thesecond and fourth interconnection layers L2 and L4 and may lack air gapsin the first and third interconnection layers L1 and L3.

Further exemplary embodiments will be now being described. Semiconductordevices according to further embodiments may include air gaps in eachinterconnection layer formed in an alternating fashion.

FIG. 14 is a plan view illustrating semiconductor devices according tostill another exemplary embodiment of the inventive concepts. FIG. 15ais a cross-sectional view corresponding to line I-I′ of FIG. 14, FIG.15b is a cross-sectional view corresponding to line II-II′ of FIG. 14,FIG. 15c is a cross-sectional view corresponding to line of FIG. 14, andFIG. 15d is a cross-sectional view corresponding to line IV-IV′ of FIG.14.

Referring to FIGS. 14 and 15 a through 15 d, a substrate 1 may havefirst through fourth regions A, B, C, and D. The first region A may beadjacent the second region B in a first direction (X-direction) and maybe adjacent the third region C in a second direction (Y-direction). Thethird region C may be adjacent the fourth region D in the firstdirection and the second region B may be adjacent the fourth region D inthe second direction.

First through fourth interconnection layers L1, L2, L3, and L4 may besequentially formed on the substrate 1. The first interconnection layerL1 may include eleventh through thirteenth conductive patterns 10 a, 10b, and 10 c which extend in the second direction. The eleventh throughthirteenth conductive patterns 10 a, 10 b, and 10 c may be parallelline-shaped patterns. First air gaps AG1 may be disposed betweenadjacent ones of the eleventh conductive patterns 10 a in the secondregion C and between adjacent ones of the twelfth conductive patterns 10b in the third region B. However, there are no air gaps between adjacentones of the eleventh conductive patterns 10 a in the first region A andbetween adjacent ones of the twelfth conductive patterns 10 b in thefourth region D.

Second air gaps AG2 may be disposed in the second interconnection layerL2. However, the location of the second air gaps AG2 may be differentfrom the first air gaps AG1. In particular, the second air gaps AG2 maybe disposed in the first region A and in the fourth region D.

Third air gaps AG3 may be disposed in the third interconnection layerL3. The location of the third air gaps AG3 may be similar to the firstair gaps AG1. Fourth air gaps AG4 may be disposed in the fourthinterconnection layer L4. The location of the fourth air gaps AG4 may besimilar to the second air gaps AG2. Operations for forming the third airgaps AG3 and the fourth air gaps AG4 may be substantially the same asthose described above with reference to FIGS. 1 through 11.

FIG. 16 is a cross-sectional view, corresponding to line I-I′ of FIG. 1,illustrating a semiconductor device according to still another exemplaryembodiment of the inventive concepts.

Referring to FIG. 16, the semiconductor device may not include any maskpatterns. The mask patterns M1, M2, M3, and M4 described above withreference to FIGS. 1-11 may be removed before forming the insulatingdiffusion barrier layers 11, 21, 31, and 41. The method of forming theother layers may be substantially the same as the method described indescription corresponding to FIGS. 1 through 11.

FIG. 17 is a cross-sectional view illustrating a semiconductor deviceaccording to still further embodiments of the inventive concepts.Referring to FIG. 17, a semiconductor device may include a fifth througheighth capping layers 9 b, 19 b, 29 b, and 39 b between mask patterns(M1, M2, M3, and M4) and interlayer dielectric layers (3, 13, 23, and33) in interconnection layers L1, L2, L3, and L4, respectively. Thefifth through eighth capping layers 9 b, 19 b, 29 b, and 39 b mayinclude metal oxynitride layers, for example, aluminum oxynitridelayers. The fifth through eighth capping layers 9 b, 19 b, 29 b, and 39b may be formed simultaneously when the first through fourth cappinglayers 9 a, 19 a, 29 a, and 39 a are formed, respectively.

FIG. 18 is a plan view illustrating a semiconductor device according tofurther embodiments of the inventive concepts. FIG. 19 is across-sectional view corresponding to line I-I′ of FIG. 18.

Referring to FIGS. 18 and 19, a first interconnection layer L1 and asecond interconnection layer L2 may be sequentially formed on asubstrate 1. The first interconnection layer L1 may include a firstinterlayer dielectric layer 3 having a first recess R1 formed therein.Eleventh conductive patterns 10 a may be disposed in the firstinterlayer dielectric layer 3 and twelfth conductive patterns 10 b maybe disposed in the first recess R1. A thirteenth conductive pattern 10 cmay be disposed at a boundary between the eleventh conductive patterns10 a and the twelfth conductive patterns 10 b. Upper surfaces of theeleventh conductive patterns 10 a and a portion of an upper surface ofthe thirteenth conductive pattern 10 c may be covered by a first maskpattern M1. The first mask pattern M1 may be covered by a firstinsulating diffusion barrier layer 11. The first insulating diffusionbarrier layer 11 may be formed in gaps between adjacent ones of thetwelfth conductive patterns 10 b and may define first air gaps AG1.

The second interconnection layer L2 may include a second interlayerdielectric layer 13 covering the first interconnection layer L1. Thesecond interlayer dielectric layer 13 may have a second recess R2defined therein on an opposite side of substrate 1 than the first recessR1. Twenty-first conductive patterns 20 a may be disposed in the secondrecess R2. Twenty-second conductive patterns 20 b may be formed in thesecond interlayer dielectric layer 13. A twenty-third conductive pattern20 c may be disposed at a boundary between the twenty-first conductivepatterns 20 a and the twenty-second conductive patterns 20 b. Each ofthe twenty-third conductive patterns 20 c extend in a direction(Y-direction) and may include a second wiring line 17, a conductive plug17 c, and a second metal diffusion barrier layer 15. The conductive plug17 c may extend from a bottom of the second wiring line 17 to thethirteenth conductive pattern 10 c. The conductive plug 17 c may be avia plug. Upper surfaces of the twenty-second conductive patterns 20 band the twenty-third conductive pattern 20 c may be covered by a secondmask pattern M2. The second mask pattern M2 may overlap the conductiveplug 17 c. A second insulating diffusion barrier layer 21 may bedisposed on the second mask pattern M2. The second insulating diffusionbarrier layer 21 may cover upper surfaces of the twenty-first conductivepatterns 20 a and sidewalls thereof. Second air gaps AG2 may be disposedbetween adjacent ones of the twenty-first conductive patterns 20 a.

A sidewall of the thirteenth conductive pattern 10 c may contact thefirst interlayer dielectric layer 3 and be positioned apart from thefirst air gaps AG1. A sidewall of the twenty-third conductive pattern 20c may contact to the second interlayer dielectric layer 13 and bepositioned apart from the first air gaps AG1. Operations for forming theother layers may be substantially the same as those described above withreference to FIGS. 1 through 11.

FIG. 20 is a plan view illustrating a semiconductor device according tofurther embodiments of the inventive concepts. FIG. 21 is across-sectional view corresponding to line I-I′ of FIG. 20.

Referring to FIGS. 20 and 21, the semiconductor device may be similar tothe device illustrated in FIGS. 1 and 2A-C, but may not have the firstthrough fourth conductive patterns 10 c, 20 c, 30 c, and 40 c at aboundary of the first region A and the second region B provided in thedevice illustrated in FIGS. 1 and 2A-2C. Interlayer dielectric layers 3through 33 and mask patterns M1 through M4 may be alternately formed ata boundary between a first region A and a second region B. Theinterlayer dielectric layers 3 through 33 and the mask patterns M1through M4 may perform as a support at the boundary. Operations, forforming the device of FIGS. 20 and 21 may be substantially similar tothose described above with reference to FIGS. 1 through 11.

FIG. 22 is a block diagram of an electronic system including asemiconductor device according to an exemplary embodiment of theinventive concepts. Referring to FIG. 22, the system 1100 may comprise acontroller 1110, an input/output device 1120, a memory device 1130, aninterface 1140, and a bus 1150. The controller 1110, the input/outputdevice 1120, the memory device 1130, and the interface 1140 maycommunicate with each other through the bus 1150. The bus 1150 maycorrespond to a path over which data can be moved between systemelements.

The controller 1110 may comprise a microprocessor, a digital signalprocessor, a microcontroller, or a similar device that can control anexecutive program. The input/output device 1120 may comprise a keypad, akeyboard, or a display. The memory device 1130 may not only save codesor data for executing the controller 1110 but also save data executed bythe controller 1110.

The system 1100 may be applied to a product that can transportinformation, e.g., a PDA (personal digital assistant), a portablecomputer, a web tablet, a wireless phone, a mobile phone, a digitalmusic player, or a memory card.

The memory device 1130 may comprise a semiconductor device, which has anon-volatile memory device according to an example embodiment of theinventive concepts.

The above-disclosed subject matter is to be considered illustrative andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments, which fall withinthe true spirit and scope of the inventive concepts. Thus, the scope ofthe inventive concepts is to be determined by the broadest permissibleinterpretation of the following claims and their equivalents, and shallnot be restricted or limited by the foregoing detailed description.

What is claimed is:
 1. A semiconductor device, comprising: a substrate;a plurality of first conductive patterns disposed on the substrate; aplurality of first air gaps, respective ones of which are disposedbetween adjacent ones of the plurality of first conductive patternsoverlying a first region of the substrate; a plurality of secondconductive patterns disposed on the first conductive patterns; aplurality of second air gaps, respective ones of which are disposedbetween adjacent ones of the plurality of second conductive patternsoverlying a second region of the substrate; and a mask pattern disposedbetween the first conductive patterns and the second conductive patternsand not overlapping the first air gaps.
 2. A semiconductor devicecomprising: a substrate; an interlayer dielectric layer on thesubstrate; first conductive lines disposed in the interlayer dielectriclayer; second conductive lines disposed in a recess in the interlayerdielectric layer; and a diffusion barrier layer disposed on and betweenadjacent ones of the second conductive lines in the recess in theinterlayer dielectric layer, the diffusion barrier layer definingrespective air gaps between sidewalls of adjacent ones of the secondconductive lines.
 3. The semiconductor device of claim 2, wherein thediffusion barrier also overlies the first conductive lines and furthercomprising a strengthening layer interposed between the interlayerdielectric layer and the diffusion barrier layer and overlying the firstconductive lines.
 4. The semiconductor device of claim 3, wherein thestrengthening layer does not overlie the second conductive lines.
 5. Thesemiconductor device of claim 2, wherein the interlayer dielectric layercomprises a first interlayer dielectric layer, wherein the diffusionbarrier layer comprises a first diffusion barrier layer, wherein the airgaps comprise first air gaps, and further comprising: a secondinterlayer dielectric layer on the first barrier diffusion layer; thirdconductive lines disposed in the interlayer dielectric layer overlyingthe second conductive lines; fourth conductive lines disposed in arecess in the second interlayer dielectric layer overlying the firstconductive lines; and a second diffusion barrier layer disposed on andbetween adjacent ones of the fourth conductive lines in the recess inthe second interlayer dielectric layer, the second diffusion barrierlayer defining respective second air gaps between sidewalls of adjacentones of the fourth conductive lines.
 6. The semiconductor device ofclaim 5, wherein the first diffusion barrier also overlies the firstconductive lines, wherein the second diffusion barrier layer alsooverlies the third conductive lines and further comprising: a firststrengthening layer interposed between the first interlayer dielectriclayer and the first diffusion barrier layer and overlying the firstconductive lines; and a second strengthening layer interposed betweenthe second interlayer dielectric layer and the second diffusion barrierlayer and overlying the third conductive lines.